Telegraphophone reproducer



w 1,645,491 0 1927' LE ROY .1. LEISHMAN TELBGRAPHOPHONE REPRODUCER Filed May 25, 1926 [AC/j: Z9 am 2/ Patented Oct. ll, 1927.

LE ROY J. LEISHMAN, F OGDEN, UTAH.

TELEGRATPHOPHONE REPRODUCER.

Application filed May 25, 1926. Serial No. 111,568.

This invention relates to reproducers and I has for its object the provision of a simple and eificient device which can be attached to an ordinary phonograph in place of the usual reproducer and positioned in a radio set to replace the detector tube without any further change in either the phonograph or the radio set. I

It is quite old to amplify phonograph music by electrical means but in every case the amplifier is a part of the phonograph and is not available for instant use as part of a radio set. The present reproducer renriors it possible to connect the phonograph to the radio set and reproduce on the loud speaker the music which produced the sound record and yet it can be removed from the radio receiver as quickly as a single tube can be replaced whereupon the radio receiving set is in condition for ordinary use for the reproduction of broadcast matter.

It is a very simple. matter to arrange a radio rechiver so that the undulations or grooves in a phonograph disk will operate it to produce changes of electric current and to send this amplified current thru an audio amplifying set wired for the purpose, but altho devices of this kind are quite old they have never gone into commercial use because 30 of the nuisance of making the connections or the expense and bother of having a separate and distinct audio set for use with the phonograph.

In the drawings- The figure shows a simple embodiment of the invention.

The casing 10 has a tubular extension 11 of such size and shape as readily to fit on the tone arm of a phonograph. The main section of the casing 10 has a cylindrical bore 12 to receive a reproducer unit. here illustrated as a modified Baldwin unit, altho obviously any other standard unit could be used. The casing has a pair of binding posts 14- which are connected to the coil 1:") on a spool held between the channel pieces 16 and .7 whi h are test in the usual Fashion to the permanent masruct the pole pieces of which are numbered 18 and lFl in the drawour.

The dia'l'racm 510 in this type or unit. is a Hat shoot ot non pivo ed centrally ot the coil lfi. No claim is made to the permanent magnet. the channels. the coil. and the diatra'gm except in the combination shown as noose pieces are standard parts of the unit. I close the open face of the casing 10 with a light metal disk 25 which is secured to the casing and also to the unit, being, in fact, the sole support of the unit. The disk 25 at its bottom has a pair of lugs 26 in which is pivoted in quite usual fashion the needle carrier 27. The vibrating arm 30 or an extension of it passes thru a central hole in the disk 25 and is fast to the diufragm 20.

The small case 40 contains a-by-pass condenser 41 of approximately one Inicrofarad and a variable resistance 42 of approximately seventy-five kilohms. The leads 44 from the case 10 make connection with a handle 45 having prongs 46 to make contact with the filament spring contact and the plate-spring contact of a radio tube socket. The handle 45 is of the same type as that used in radio testing devices save that it only has two of the prongs electrically connected with the lead-in wires 44.

The usual phonograph reproducer is disconnected and the casing 10 is slipped on the tone arm in its stead and the handle 45 is placed in the detector socket otany ordinary radio set, the detector tube itself being removed. Since one of the prongs 4-6 makes contact with the plate spring and the other effective prong makes contact with the filament spring, the B-battery current will flow, and the vibration of the arm 30 by the needle following the lateral groove in the record, will vary the current so as to reproduce the sound in greatly magnifiedvolume thru the loud speaker. The audio frequency by-pass condenser being in series with the reproducer blocks the direct current while permitting the audio variations to pass without restriction. and the variable resistance renders it facile to va 'y the volume to suit the location of the set.

1. in combination, a telegraphophone sound box. a prong carrying member readily iuscrtablc in a radio tube socket to engage a plurality of the contacts thcrcot. and a pair of flexible wires connecting the sound box and member.

The device of claim 1 having a by-pass condenser in circuit between the sound box and member.

3. The device oirlaim 1 having a variable resistance in circuit be ween the sound box and member.

@ ma a ial 4. The device of claim 1 having a by-pass condenser and a variable resistance in circuit between the sound box and member.

. 5. The device of claim 1 in which the 5 sound box is readily detachable from the tone arm of a phonograph.

6. The device of claim 1 having a by pass condenser and a variable resistance in circuit between the sound box and the prong carrying member, and in which the sound 10 box is readily detachable from the tone arm or a phonograph llntestimony whereof I aliix my signature.

LE ROY J. LEISHMAN. 

